This description relates to early warning and collision avoidance.
Collision avoidance systems have become abundant. King et al. (US patent publication 2007/0276600 A1, 2007), for example, described placing sensors ahead of an intersection and applying a physics-based decision rule to predict if two vehicles are about to crash at the intersection based on heading and speed.
In Aoude et al. (U.S. Pat. No. 9,129,519 B2, 2015, the entire contents of which are incorporated here by reference) the behavior of drivers is monitored and modeled to allow for the prediction and prevention of a violation in traffic situations at intersections.
Collision avoidance is the main defense against injury and loss of life and property in ground transportation. Providing early warning of dangerous situations aids collision avoidance.